Engine compartment structure of a work machine

ABSTRACT

In a structure of an engine compartment in a work machine such as a tractor, a bulldozer, a hydraulic excavator, a wheel loader, the air taken through vents, which are formed on side covers and a hood covering the engine compartment, is supplied directly to a radiator via ducts which are provided on the side of the side covers and the side of the hood respectively. The ducts cover the vents, thereby preventing noise within the engine compartment from escaping to the outside. Therefore it is possible to increase a cooling efficiency of the radiator by supplying the outside air, which does not take up the heat of an engine, directly to the radiator, as well as to reduce the engine sound and prevent the engine noise from escaping.

BACKGROUND OF INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a structure of an engine compartment in a work machine, for example, a tractor, a bulldozer, a hydraulic excavator, a wheel loader and the like. More particularly, it relates to the structure which is capable of improving a cooling efficiency with respect to a radiator, reducing an engine sound and preventing a noise from the engine compartment.

[0003] 2. Description of the Related Art

[0004] In general, such a structure of the inside of an engine compartment in a work machine has been known that a radiator and an oil cooler are arranged in a front portion of the engine or the like for cooling the radiator and the oil cooler by a cooling fan. The cooling fan is directly driven by means of a belt drive or the like by the engine, or is driven by an electric motor or a hydraulic motor, which is rotated and controlled independently of the engine rotation. For the cooling of a radiator, an oil cooler and the like by means of a cooling fan, there are such a type that cools the radiator and the oil cooler by directly sucking the outside air from a front face of the radiator, or such a type that cools the engine by the outside air introduced from the engine side and then discharges the cold blast by means of the cooling fan while sucking the cold blast so as to cool the radiator and the oil cooler. Alternatively, there may be such a type that is provided with both of the above types.

[0005] For example, Japanese Patent Application Laid-Open No. 2001-27130 describes the type of cooling the radiator and the oil cooler by directly sucking the outside air from the front face of the radiator.

[0006] The description of the above-mentioned publication will be given with reference to FIG. 7. As shown in FIG. 7, the outside air taken through a vent 21 on a front side of a hood 20 is sucked by a radiator cooling fan 22 so as to cool a radiator 23, and thereafter it is discharged to the side of the outside air through an outlet grill 24 which are provided on the right and left side portions of the hood 20. The engine 25 is hermetically covered by a shielding plate 26 so as to prevent an engine noise from escaping to the outside. Further, the vent 21 for cooling the engine is provided in the shielding plate 26 disposed at a lower portion of the engine 25. The outside air sucked through the vent 21 by an engine cooling fan 27 is discharged to the side of the outside air through a duct 28 after cooling the engine 25.

[0007] Japanese Patent Application Laid-Open No. 2001-182535 discloses such a type that cools the engine with the outside air introduced from the engine side and thereafter discharge the cold blast forward while sucking the cold blast by means of a cooling fan so as to cool a radiator and an oil cooler.

[0008] The description of the above-mentioned publication will be given with reference to FIG. 8. As shown in FIG. 8, the cooling air, which cools the engine 25, is sucked by a cooling fan 30, which is driven by a hydraulic motor 29 rotated and controlled independently of the rotation of the engine 25. Then the cooling air is discharged to a front side of the hood 20 while cooling the radiator 23 and an oil cooler 31.

[0009] Further, in order to obtain an optimum cooling efficiency by means of the cooling fan 30, a rotation frequency of the cooling fan 30 is controlled by detecting a cooling water temperature, a working fluid temperature and an engine speed and then controlling a rotation speed of the hydraulic motor 29 in correspondence to the cooling water temperature, the working fluid temperature and the engine rotation number. Accordingly, in the case that the outside air temperature, the cooling water temperature and the working fluid temperature are all lower than the set temperatures at the time when the engine is being started, the rotation of the cooling fan 30 is made to be kept at rest even after the engine starts. In the case that the cooling temperature rises to a temperature equal to or more than the set temperature and the working fluid temperature is lower than the set temperature, the outside air is introduced from the front side of the radiator 23 by reversely rotating the cooling fan 30. Then the working fluid within the oil cooler 31 is warmed up by a warm breeze, which has been warmed up by the radiator 23 and, at the same time, the refuses accumulated in the radiator 23 and the like are removed by an adverse wind. In the case that both of the cooling water temperature and the working fluid temperature become equal to or more than the set temperatures, the cold blast which has cooled the engine 25 is sucked by normally rotating the cooling fan 30, whereby both of the cooling water and the working fluid are cooled. Accordingly this prior art aims to shorten a warming up time of the hydraulic machine and to improve a cooling efficiency by removing the refuses accumulated in the radiator 23 and the oil cooler 31.

[0010] However, in the former (Japanese Patent Application Laid-Open No. 2001-27130) of the above mentioned prior arts, since the engine compartment is covered by the shielding plate in a sealed state, the temperature inside the engine compartment becomes high due to a heat generation of the engine. Therefore it becomes necessary to further increase the rotation frequencies of the radiator cooling fan and the engine cooling fan for the purpose of cooling the engine. Accordingly, since the engine speed gets high and the engine generates more heat, it is hard to improve the cooling efficiency. Further, it is required to provide the engine cooling fan and the radiator cooling fan respectively, which makes the structure of the inside of the engine compartment complex.

[0011] In the latter (the structure described in Japanese Patent Application Laid-Open No. 2001-182535) of the above mentioned prior arts, the rotation frequency of the cooling fan is controlled by controlling the rotation speed of the hydraulic motor in correspondence to the cooling water temperature, the working fluid temperature and the engine speed in order that the optimum cooling efficiency can be obtained. However, since the cold blast which cools the engine is used for cooling the radiator and the oil cooler, the cooling efficiency with respect to the radiator is deteriorated when the temperature of the cold blast which has cooled the engine rises due to the heat generation of the engine. As a result, it becomes necessary to increase the rotation frequency of the cooling fan, which makes the engine sound louder.

SUMMARY OF THE INVENTION

[0012] The problems as mentioned above can be effectively solved by the present invention.

[0013] That is, in accordance with the present invention, there is provided an engine compartment structure of a work machine comprising: a pair of first ducts interposed between an engine and first vents on side covers covering right and left sides of an engine compartment, said pair of first ducts introducing air taken through the first vents directly to a radiator.

[0014] In this invention, the ducts are provided at the right and left side covers within a space between the engine and the vents on the right and left side covers which covering the engine compartment. Further, the air taken through the vents by the ducts can be directly introduced to the radiator without taking up any heat of the engine generated, so that it is possible to improve a cooling efficiency of the radiator. Further, since it is possible to prevent the engine noise from escaping out of the vents on the respective side covers by means of the ducts, a sound isolation can be enhanced. In the case that a sound insulator is provided in the ducts, the sound isolation can be more effective.

[0015] Further, the vents can be a plurality of slit-like opening portions or formed by a mesh sheet material. Further, the vents can be a plurality of punch holes or the like. The vents can be formed on the side covers by mounted metal plates having vents formed thereon, mesh sheets or the like to the side covers. Alternatively, the vents may be formed on the side covers directly. Whichever way the vents are formed, it is possible to prevent refuses, dusts and the like from being carried to the radiator so as to choke up the radiator as far as the size of the vents as an air intake port is adjusted so as to prevent the refuses, the dusts and the like from goring through the vents. Further, it is possible to maintain an inside of the engine compartment in a clean state.

[0016] It is desirable that an opening portion of the duct toward the radiator is open to the side of the air suction of the cooling fan so that the radiator can be cooled by the outside air supplied from the opening portion. In the case that the cooling fan is capable of rotating forward and backward, the opening portion may be arranged so that the outside air through the ducts is supplied to the engine-side rotation surface of the cooling fan and the front face side of the radiator to which the outside air is sucked.

[0017] The duct may be mounted to such a place as a side cover, a hood where the duct can be mounted. At this time, in the case that the ducts are detachably mounted by bolts or the like, it is possible to perform an inspection for maintenance in a large space inside of the engine compartment by means of removing the ducts at the time of the inspection for maintenance in the engine compartment. Then when the ducts are mounted after the inspection for maintenance, the effect of the present invention can be further exerted.

[0018] It is possible to prevent the sound within the engine compartment from escaping to the outside through the vents on the side covers by using the ducts if the ducts are arranged so as to cover all of the vents, thereby improving the sound isolation as mentioned above.

[0019] The cold blast for cooling the engine can be taken through vents or the like formed at the lower portion of the engine. Further, the cooling fan can cool not only a radiator but also an oil cooler or the like if the oil cooler or the like is placed in front of the cooling fan.

[0020] As for the structure of the ducts in the engine compartment, it is preferable that said pair of first ducts are mounted to the right and left side covers. In accordance with the present invention, the ducts mounted to the side covers are integrally taken out together with the side covers at the time when the side covers, which can be freely opened and closed, are opened.

[0021] Accordingly, it is possible to perform an inspection for maintenance in the engine compartment only if the side covers are opened without taking out the ducts. When the side covers are opened, the side covers can be kept widely open by a locking device such as a hook locking the side covers, thereby facilitating the inspection for maintenance. When the side covers are closed after the inspection for maintenance for the engine compartment, the ducts are set within the engine compartment as they are.

[0022] Further preferably, the engine compartment structure further comprises at least one second duct interposed between the engine and second vents on a hood covering an upper portion of the engine compartment, said second duct introducing air taken through the second vents directly to the radiator.

[0023] In accordance with the present invention, the ducts are also provided on the hood which covers an upper face of the engine compartment. An intake amount of the outside air to the radiator is increased by providing the ducts on the hood. Therefore, it is possible to increase a cooling efficiency for the radiator by the cooling fan.

[0024] In the present invention, the object to be cooled by the cooling fan is not limited to a radiator. An oil cooler or the like can be also cooled by the cooling fan.

[0025] It is desirable that the radiator-side opening portion of the duct provided on the hood are open to the air-suction-side of the cooling fan so that it is possible to cool the radiator by the outside air supplied through the opening portion. In the case that the cooling fan is capable of rotating forward and backward, the opening portion may be arranged so that the outside air is supplied via the ducts to the engine-side rotation surface of the cooling fan and the front-face side of the radiator to which the outside air is sucked.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a perspective view of a peripheral part of an engine compartment of a work machine;

[0027]FIG. 2 is a perspective view of an inside of the engine compartment, from which a hood and side covers are taken away;

[0028]FIG. 3 is a front view of the side cover;

[0029]FIG. 4 is a front view of a modified example of the side cover;

[0030]FIG. 5 is a front view of the hood portion;

[0031]FIG. 6 is a front view of a modified embodiment of the hood portion;

[0032]FIG. 7 is a view which shows a prior art; and

[0033]FIG. 8 is a view which shows another prior art.

DESCRIPTION OF EMBODIMENT

[0034] Preferred embodiment in accordance with the present invention will be described in detail with reference to the accompanying drawings.

[0035]FIG. 1 schematically shows a perspective view of side covers 2 and a hood 3 which cover an engine compartment 1. The side covers 2, which are on right and left sides, can be opened and closed respectively by hinges 5. The side cover 2 is attached with a metal plate 11, which is provided with a plurality of punch holes to form vents 4. In place of the punch holes, the vents may be a metal plate which is formed with a plurality of slit-like opening portions, or a mesh sheet material. Further, in place of using the metal plate, punch holes or slit-like opening portions may be formed directly on the side cover 2.

[0036]FIG. 2 schematically shows a perspective view of the inside of the engine compartment 1 from which the side covers 2 and the hood 3 are taken away. An engine 10 and the other devices are arranged within the engine compartment 1. A cooling fan 7 and a radiator 6 are arranged on a front side of the engine 10. The cooling fan 7 rotates in accordance with the rotation of the engine 10. The cooling fan 7 sucks a cooling air which has cooled the engine 10 by introducing the outside air through vents (not shown) formed at a lower portion of the engine 10, as well as the outside air which is directly introduced through ducts 8 and 9, thereby cooling the radiator 6. It is desirable that opening portions of the ducts 8 and 9 on the radiator side are open to the air suction side of the cooling fan so that the radiator can be cooled by the outside air supplied from the opening portions. In this case, the cooling fan can be driven by using an electric motor or a hydraulic motor which is provided independently of the engine 10. When the electric motor or the hydraulic motor provided independently of the engine 10 is the one that is capable of rotating both forward and backward, the cooling fan 7 can rotate forward and backward. Therefore, the opening portions can be arranged so that the outside air is supplied via the ducts to the engine-side rotation surface of the cooling fan and the front face side of the radiator to which the outside air is sucked.

[0037]FIG. 3 is a view showing a structure of one of the right and left side covers 2. Since the structure of the side cover 2 on one side is the same as the other one, description of the structure of the other one is omitted here.

[0038] The side cover 2 is mounted to the hood 3 by the hinges 5 in such a manner that it can be opened and closed. The side cover 2 is fixed at a closed position and an open position by means of a locking device (not shown). The metal plate 11 formed with a plurality of ventilation holes is mounted to the side cover 2. A flange portion 13, which is formed by bending a portion of the duct 8 on the side of the side cover 2, is mounted to the side cover 2 by means of bolts, so that the ventilation holes on the metal plate 11 are all covered by the duct 8. Since the ventilation holes on the metal plate 11 are all covered by the duct 8, it is possible to prevent the noise generated within the engine compartment 1 from escaping to the outside through the ventilation holes.

[0039] When the side cover 2 is rotated with respect to the hinges 5, the duct 8 is rotated integrally with the side cover 2 so as to come out of the engine compartment. Therefore it is possible to inspect the inside of the engine compartment 1 for maintenance while the side cover 2 is kept open. In this case, it is necessary that the duct 8 is so structured that it does not contact with the opening portion of the side cover when the side cover is opened or closed so as to interfere with the opening and closing of the side cover.

[0040] The duct 9 is mounted to the hood 3 by bolts 12. The duct 9 can be detached at the time of inspection of the inner side of the engine compartment for maintenance, so that it is possible to obtain a working space sufficient for the inspection for maintenance.

[0041]FIG. 4 shows a modified example in which the duct 8 on the side of the side cover 2 is mounted to the hood 3 side. Since the duct 8 is not mounted to the side cover 2, the duct 8 can be opened by rotating the side cover 2 around the hinges 5 and opening the side cover 2. As a result, it is possible to remove refuses, dusts or the like which are accumulated within the duct 8. Further, if the duct 8 is detached from the hood 3 in this state, the inspection of the inside of the engine compartment for maintenance can be easily performed.

[0042]FIGS. 5 and 6 show the ducts 9 which are attached to the hoods 3. The duct 9 shown in FIG. 5 is composed of a single duct 9. The duct 9 shown in FIG. 6 is composed of two independent parts. It is possible to determine whether the duct 9 attached to the hood 3 should be composed of a single part or plural parts depending on the space condition within the engine compartment 1. The vents 4 formed on the hood 3 can be formed by such a means as applying a metal plate formed with a plurality of holes or slits, in the same manner as the case of the side cover 2 formed with the vents 4. The air supplied through the vents 4 on the upper surface of hood 3 is used for cooling the radiator. The description is omitted here with respect to the opening position of the duct 9 on the side of the radiator, because the opening position is the same as that of the duct 8 on the side of the side cover 2 as mentioned above.

[0043] Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims. 

What is claimed:
 1. An engine compartment structure of a work machine comprising: a pair of first ducts interposed between an engine and first vents on side covers covering right and left sides of an engine compartment, said pair of first ducts introducing air taken through the first vents directly to a radiator.
 2. An engine compartment structure according to claim 1, wherein said pair of first ducts are mounted to said right and left side covers.
 3. An engine compartment structure according to claim 1, further comprising at least one second duct interposed between the engine and second vents on a hood covering an upper portion of the engine compartment, said second duct introducing air taken through the second vents directly to the radiator.
 4. An engine compartment structure according to claim 2, further comprising at least one second duct interposed between the engine and second vents on a hood covering an upper portion of the engine compartment, said second duct introducing air taken through the second vents directly to the radiator. 